ICT Notes by Shawon.docx

# Edexcel IGCSE ICT Revision Notes ## Introduction ### Edexcel IGCSE ICT Revision Notes By Shawon Notes www.shawonnotes.com ## Topic Areas - **Hardware** - Types of ICT systems - Importance of ICT - Input Devices - Keyboard - Mouse - Tracker Ball - J...

# Edexcel IGCSE ICT Revision Notes ## Introduction ### Edexcel IGCSE ICT Revision Notes By Shawon Notes www.shawonnotes.com ## Topic Areas - **Hardware** - Types of ICT systems - Importance of ICT - Input Devices - Keyboard - Mouse - Tracker Ball - Joystick - Graphics Tablet - Scanner - Digital Camera - Webcam - Microphone - Touch Screen - Optical Mark Recognition - Optical Character Recognition (OCR) - Bar Code Scanner - Biometric Scanner - Magnetic Stripe Reader - Chip and Pin - Sensors - Processors - CPU - Graphic Card - Sound Card - Output Devices - Monitor - Printer - Plotter - Data Projector - Speakers - Control Devices - Configuring an ICT system to meet need. - **Software** - System Software - Application Software - **Backing Storage** - Data capacity terminology - Main Memory - RAM - ROM - Storage devices - Hard disk drive (HDD) - RAID - External Hard Disks - Optical Disks - Compact Discs (CDs) - Digital Versatile Discs - DVDs (CD-R, DVD-R, DVD-RW, DVD-RAM, HD DVD, Blu-Ray) - Flash memory - Magnetic tape - **Networking** - Types of network - Benefits of establishing network - Network security - Requirements for connecting to the internet - Features of common Internet services - Intranet - **Impact of ICT** - Impact of ICT on Individuals, Organisations and Society - Legal issues in use/misuse of ICT - Legal restraints on the use of information - Safety - Computer crime - Securing data and personal information - Personal responsibility on the internet ## Hardware ### Types of ICT systems: - **PCs:** A desktop PC usually has these basic components: a monitor, a keyboard, a system unit and a mouse. - **Laptops:** A laptop computer is slightly larger and much heavier than an A4 file. - **Notebooks:** A notebook computer is a small laptop computer that is about as big as an oversized book. A notebook computer is likely to be half the size of a laptop and is lighter and easier to carry. - **Netbooks:** A netbook computer is a very small laptop that is optimized for internet and email access. It is intended to be light and easy to carry and has a long battery life. - **Hand-held:** A handheld computer or Personal Digital Assistant (PDA) or palmtop can fit in one hand or in your pocket, but it is too small for general work. A PDA usually has a touch-sensitive screen. Although PDAs can be temporarily attached to a keyboard, you cannot comfortably type a long document into a PDA. - **Smartphones:** A smart phone is a mobile phone with the functions of a PDA. Handheld computing devices can perform a range of activities such as personal record-keeping and satellite navigation. - **Mainframe:** A mainframe computer is a very large and expensive computercapable of supporting hundreds, or even thousands, of users simultaneously. - **Supercomputers:** These are the fastest type of computers. Supercomputers are very expensive and are employed for specialized applicationsthat require immense amounts of mathematical calculations. For example, weather forecasting requires a supercomputer. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration. - **Embedded Computers:** An embedded computer is designed for and built into a specific application where it will perform a limited range of dedicatedfunctions. The size and functionality of an embedded computer depends on the application. They may be very small devices built into a single microchip and may control - **Games consoles:** A games console is a PC that is designed specifically for playing games. ## Software ### System Software - Operating System: The Operating System (OS) controls the computer. It runs between the hardware and the application software, enabling applications to use the Computer's hardware. It has several functions including: - Input and Output control - Error handling - Resource allocation - User interface - Allowing users to give commands to the computer. - File handling ### Application Software - Office Productivity Tools: These tools help users work more efficiently when doing tasks in the office. - Word Processing - Editing and creating text documents - Desktop Publishing - Creating professional looking documents - Spreadsheet - Manipulating data and calculations - Database - Storing and retrieving data quickly and efficiently - Web Authoring: This software create a website - a collection of web pages that can accessed via the internet. The web pages usually include text and graphics and are written using HTML. - Image and Sound Editing: This edits pictures, photographs, videos and music. - Presentation Software: This software prepares and delivers presentations. It includes the creation of slides with mainly text and graphics. - Project Management Software: This software tracks and charts timelines for tasks and events needed to complete a project. ## Backing Storage ### Data Storage Capacity terminology: - 1 Kilobyte or 1 KB = 1024 bytes - 1 Megabyte or 1 MB = 1024 KB or 1 048 576 bytes - 1 Gigabyte or 1 GB = 1024 MB - 1 Terabyte or 1 TB = 1024 GB ### Main Memory - Memory is a device used to store programmes temporarily or permanently. - Main Memory: Any data or instructions that are to be processed by the CPU must be placed into main memory - this is often known as *primary storage*. - RAM (Random Access Memory): This can be written to, read from and edited. Data can be accessed in any order. It is a volatile memory, so when the computer is switched off the data will be cleared. - ROM (Read Only Memory): This memory can also be accessed randomly, but the data stored in it cannot be changed. It is used for permanent data, necessary for the computer system to operate. It is non-volatile, so it retains what data it contains when the computer is switched off. - **Types of ROM** - PROM - Programmable Read Only Module: This has no data locked onto when first manufactured. A company can then lock their own data in place, so it cannot change. - EPROM - Erasable Programmable Read Only Module: This has a window on the chip where the data can be erased using a special light shining on it. ### Comparing RAM and ROM | Feature | RAM | ROM | |---|---|---| | **Data Access** | Can be written to and read from | Can only be read from | | **Data Storage** | Holds program and data currently being used | Holds all the instructions that the CPU needs to operate | | **Volatility** | Data is cleared when computer is switched off | Data is retained when the computer is switched off | | **Location** | RAM microchips are supplied as a module plugged to the motherboard | ROM microchips are installed on the motherboard | ### Storage Devices: - **Hard Disk Drive (HDD):** This is a data storage device used for storing and retrieving digital information using rapidly rotating disks (platters) coated with magnetic material. The data is stored in concentric tracks which are grouped in cylinders. Each surface of the disk has a read/write head that traverses over the rotating disk. This formula can determine the total storage space: *number of readable sides x nnumber of cylinders x sector per track x bytes per sector* - **RAID (Redundant Array of Inexpensive Drives):** This stores a set of copies of data on different hard drives. If one drive fails, the data can be recovered from one of the other drives. - **External Hard Disks:** These hard drives come in a separate case and are robust, small and lightweight. They can easily be connected to any computer with a USB socket. - **Optical Disks:** This is a storage device made from plastic and usually has a spiral track of data etched on the surface. - **Compact Discs (CDs):** A typical CD stores around 700 MB on one side. CD drives read the data using a laser beam. - **Digital Versatile Discs (DVDs):** They are similar to CDs and store up to 4.7GB (single-sided, single layer). A dual-layer DVD stores up to 18 GB and a dual-sided, dual-layer DVD can store up to 36 GB. There are several types of CDs and DVDs: - *CD-R and DVD-R:* These can only be written to once but can be read thereafter. They are often used to back up data. - *CD-RW and DVD-RW:* These can be written to multiple times but the data can be erased. - *DVD-RAM:* These may be sealed in a cartridge and can be rewritten hundreds of thousands of times. - *HD DVD:* This format is similar to DVD but stores higher definition images. It was created to succeed DVD, but a rival format, Blu-ray, became more popular. - *Blu-ray:* These disks are similar in size to CDs, but they store a larger amount of data. A single sided DVD can store up to 50 GB, making them more compact than a dual-layer CD. - **Flash Memory:** This is a type of EPROM where data can be reset quickly and easily so it can be written to, read from and edited. It is used for the BIOS of most PCs and memory cards for recording data in devices like mobile phones, cameras, and game consoles. There are several types of memory cards, such as Compact Flash, Secure Digital, mini SD, and other types. A Flash pen has a USB connector and is used to transfer data from one computer to another. - **Magnetic Tape:** This is wrapped around a reel to offer large storage space. It can only access data sequentially, so it is used for backing up data and not for quicker actions. ## Networking ### Types of Network - **Local Area Networks (LANs):** This is a set of computers that can share peripherals, data and communicate with each other. They can be located in the same building, office, or room. Each computer can operate as its own system, and as part of the network. - **Client/Server Network:** This network has one or more computers that act as the server. Each client computer communicates through the server, which has more processing power than a client computer. Each server can have separate functions, for example, a file server, print server, etc. . - **Peer-to-Peer Network:** This network allows every computer to communicate directly with each other. They are best for a smaller network of computers. - **Cabled LANs:** These use cables to connect computers and devices together. The network cable connects to a network interface card (NIC) in each computer. - **Wireless LAN (WLAN):** This connects computers together with a wireless link. They use three sets of components: wireless access points, wireless network interface cards (NICS), and routers. - **Wide Area Networks (WANs):** These networks connect the internet to other networks and connect networks across multiple geographical locations - they could be across a city, country or internationally. They use high-speed telephone lines, fibre optic cables, microwave links, and satellite links. - **IP Address:** This is a unique address for each device connected to the Internet. It is a 32-bit address made from four sets of digits that are separated by full stops. It can be static or dynamic. ### Benefits of establishing a network: - Sharing peripherals from several computers - Sharing data continuously - Communicating easily - Accessing the internet simultaneously - Streaming media - Distributing software ### Network Security - **Threats** - Hacking: Unauthorised access to a computer and its files. This can also include personal information, such as emails, bank information, etc. - Spam: Unsolicited emails - Virus: Malicious software installed on a computer without the user's permission. - Phishing: Deception attempts to gain access to your personal information. - Pharming: Collecting personal information by redirecting users to fake websites. - Adware: Unsolicited advertising that appears in pop-up windows. - Access to inappropriate information: For example, a child accessing a site with adult content. - Cookies: Data storage files stored on a user's device. - **Protection** - Use a strong password and username - don't share them - Use a *firewall:* This protects against attacks by monitoring network traffic and blocks suspicious connections. - Use *WEP (Wired Equivalent Privacy) or WPA (Wi-Fi Protected Access)* codes to prevent unauthorised connections to a wireless network. - *Encrypt data:* This prevents hackers from accessing and accessing your data. - Use a *transaction log:* To record actions taken on a computer system, so you can identify hackers. - Use a *spam filter:* To block unwanted emails and prevent them from reaching your inbox. - Use *antivirus software:* This scans for viruses and removes them. - Use a *cookie manager:* To block or delete cookies when browsing websites. - Use *parental controls:* This protects a user from accessing unsuitable sites. - Restrict user file access rights: This stops users from accessing areas of a computer system that they should not have access to. ## Requirements for Connecting to the Internet ### Hardware - **Modem:** This connects a computer to the internet over a telephone line. - **Router:** This connects several computers to the internet wirelessly, giving them access at the same time. - **Gateway:** This connects the internet to a different network. ### Software - **Web browser:** This enables you to access data on the web. - **Email client:** This enables users to send and receive emails. ## Features of Common Internet Services - **Source of Services:** To access the internet, users need to subscribe to an **ISP (Internet Service Provider)**. - **Uses:** - Viewing web pages - Using a search engine - Sending emails - Online shopping - Online banking - Customer Support - Software distribution - Discussion groups - mailing lists, bulletin boards, newsgroups - Online conferences - Online chat - Web rings - Web broadcasting - Advertising - Creating your own website - Downloading or uploading digital media - Publishing online diaries - Using a wiki ## Intranet An intranet is a local version of the internet that is located within an organisation or company. It offers similar features as the Internet, but is limited to users within that company. **Examples of Intranet use:** - Notice boards - Staff directories - Company reports - Job adverts - Newsletters - Training manuals ## Impact of ICT **Positive Impacts** - Payroll systems - Online air booking systems - Supermarket stock control - Online banking - Using debit and credit cards - Computer-aided design - Production and manufacturing speed - Forecasting the weather - Robot use in industry - Development of education systems - Improved law enforcement - Advancements in healthcare - Entertainment and leisure <start_of_image> Cities and countries have benefited from the use of ICT, but areas of unemployment have increased as technology replaces some human tasks. **Negative Impacts** - **Increased Unemployment:** Workers have been displaced by technology and computers. - **Manufacturing:** Computer-controlled robots are used in manufacturing, which can be more cost-effective than employees. - **Secretarial Work:** Office workers can now type and print documents themselves. - **Accounting:** Spreadsheets can be used to perform accounting tasks. - **Newspaper Printing:** Computers are used to lay out and print newspapers, decreasing the need for skilled printers. ## Legal Issues Relating to the Use/Misuse of ICT and Constraints There are a number of legal constraints in the use of ICT. * **Computer Crime:** This is possible due to the widespread use of ICT systems. * **Software Piracy:** Copying, downloading, using or selling software without the correct license is theft. * **Copyright violation:** Copying or downloading music or pictures without the correct licence. * **Hacking:** Gaining unauthorised access into an ICT system. * **Identity theft:** The theft of personal information that is stored on a computer, which can then be used to commit crimes. * **Phishing:** This is used to steal information by sending emails that appear to be from a legitimate organisation. ## Legal Constraints on the Use of Information **Personal Data:** There are eight principles about using personal data: 1. A person must be told when their data is collected. 2. Data must only be used for the purpose given when it was collected. 3. Data must not be disclosed without the consent of the person concerned. 4. Data must be kept secure. 5. A person whose data is being collected must be told who is collecting it. 6. A person must be allowed to access their data and make corrections if it is not accurate 7. Data must not be transferred to another country that has weaker data protection laws 8. There must be a method by which people can check that data holders are complying with the principles. **Downloading Content:** There are other rules to consider when downloading content digitally: 1. The Internet is international. What may be legal to upload and download in one country, may be breaching copyright or some other law if it is downloaded in another country. 2. Licenses and permissions come in many forms. What may be free to download for e.g. a student in full time education, may need to be paid for by anyone else. 3. Different types of download may be covered by different laws. Most material has to comply with copyright law, but an item such as a computer programme, or part of one, may be protected by a patent as well. ## Safety ### Effects on User's Health - **Ergonomics:** This is important to help reduce the risk of injuries by ensuring a safe and comfortable working environment for users who use ICT. - **Repetitive Strain Injury (RSI):** This is damage to tendons, nerves, muscles and soft tissue that can be caused by the use of a keyboard or mouse. - **Eye Problem:** Constant use of the monitor can cause eye strain. - **Backache:** Sitting incorrectly can cause backache. - **Fatigue and Headaches:** These can be caused by long periods of time spent using the computer. - **Trip Hazards:** Untidy cables can cause trip hazards. - **Electric Shock:** This is a risk when using any electrical device. ## Computer Crime: ### Types of Crime - **Software Piracy:** Copying, downloading, using or selling software without an appropriate license. - **Copyright Violation:** Copying or downloading pictures, music, or videos without obtaining the correct license. - **Hacking:** Unauthorised access to an IT system. - **Identity Theft:** Stealing information about a user using a computer. - **Phishing:** Using emails to deceive people into giving up their personal information. ## Securing Data and Personal Information: - **Physical Safeguards:** This involves protecting physical hardware and software from theft or damage. This can include: - Access controls (locks, security cards, biometric recognition) - Data backups - Hardware protection from fires, floods, and theft. - **Software Safeguards:** This involves protecting software from theft and damage: - Access permissions for users - File-level passwords - Virus scanners to prevent viruses from getting on a computer. - Firewalls to prevent malicious access to a computer - Data encryption to scramble the data and protect from unauthorised access. - Transaction logs to track user actions. ## Personal Responsibility on the Internet - The way that users behave online has a social impact, so users are responsible for keeping data secure and respecting the online community. - Be careful about who you share personal data with, and don’t publish details on a public website. - Don’t publish personal details about others without their permission. - Don’t copy, use or share copyrighted content, like software, images, music, or videos. - Be polite and reasonable, avoiding online harassment or bullying.